Engine lubricant and process of making



Patented Nov. 25, 1930 UNITED STATES PATENT OFFICE ROSCOE E. CLOUGH, OF PALO ALTO, CALIFORNIA, ASSIGNOR 'IO CASTORLUBE REFINING CO., OF SAN FRANCISCO, CALIFORNIA, A CORPORATION OF CALIFORNIA ENGINE LUBRICANT AND PROCESS OF MAKING No Drawing.

This invention relates to lubricants for internal combustion engines and has for its objects the production of a stable combination or blend of castor and mineral oil with- 5 out the addition of blending agents, as well as the steps of treating the castor oil which make the blend possible.

The value of a combination of castor and mineral oil as a lubricant for internal com- 10 bustion engines has been known for some time, but in order to make such blends it has been necessary to incorporate other things which detracted from its value, for the reason that castor oil will not remain mixed with a mineral lubricating oil.

I have discovered that by certain heat treatment of the castor oil before mixing with the mineral oil that a perfect and permanent blend is obtained which will not separate even under the extreme heat of the enginewhich heretofore has always broken up mixtures of castor and mineral oils.

Castor oil itself appears to be an emulsion containing considerable water and other liquids of uncertain composition which may Application filed April 13, 1927. Serial No. 183,614.

Also to be watched is the amount of extraction from the castor oil, since an extraction exceeding 4.2% will bring it into the gumming condition which will make it impossible of use for compounding under the Castorlube method.

The product of the heat treatment when properly carried out is a modified castor oil having a viscosity of 1000 seconds 100 F. and 121 seconds 210 F. (Saybolt universal viscosimeter) As an engine lubricant for modern internal combustion engines I mix the above product with from approximately 20% to 98% of good mineral oil. The proportions may be varied in the compound as desired and remain fully compounded.

I claim:

A lubricating compound comprising castor oil, heat treated at a temperature not to exceed 590 F. until no more than 4.2% of the total Weight of the oil has been removed under atmospheric conditions, mixed with mineral oil.

ROSCOE E. GLOUGH.

be separated by special heat treatment and the remaining castor oil will then blend permanently with the mineral oil in any proportion.

To treat the castor oil I heat a quantity in a still, beginning with a gentle fire and increase the temperature at the rate of one degree Fahrenheit per minute.

When the oil reaches a temperature of 480 F. the vapors will come off of the oil and will condense to a liquid composed mostly of free fatty acids and water.

When the heat reaches 540 F. it is maintained at this temperature until 4.1 per cent of the contents of the still has passed over.

By careful measurement of the initial oil charge in gallons and multiplying the gallons by 8 (pounds per gal.) then multiplying the result by the factor .041 the exact amount in pounds to be extracted may be predetermined.

Great care must be exercised in raising the heat of the oil gradually, for'if too rapid the oil will be scorched and rendered useless. Also a temperature in excess of 570 F. will crack the oil and spoil it. 

